Suction nozzle for holding component by suction

ABSTRACT

A suction nozzle ( 21 ) has an outer nozzle member ( 30 ), a nozzle body ( 40 ), and an urging member ( 50 ) for urging the nozzle body ( 40 ) in a direction away from the outer nozzle member ( 30 ). The suction nozzle ( 21 ) also has a spring accommodation chamber ( 60 ) defined by at least a wall surface of a nozzle body accommodation bore ( 32 ) and a proximal end face ( 40   c ) of the nozzle body ( 40 ). The spring accommodation chamber ( 60 ) is shut off from first and second suction passages ( 31, 32 ) and communicates with atmosphere. The urging member ( 50 ) is housed in the spring accommodation chamber ( 60 ).

TECHNICAL FIELD

[0001] The present invention relates to a suction nozzle, and moreparticularly, relates to a suction nozzle for holding a component bysuction used in a component mounting apparatus for mounting a componentsuch as an electronic component on a circuit formation object such as acircuit board.

BACKGROUND ART

[0002]FIG. 13 illustrates a conventional suction nozzle 1 used forholding an electronic component B by suction in an electronic componentmounting apparatus.

[0003] The suction nozzle 1 includes: an outer nozzle member 2 having afirst suction passage 2 a; a nozzle body 3 provided to be displaceablewith respect to the outer nozzle member 2 and having a second suctionpassage 3 a for communicating with the first suction passage 2 a; and aspring 4 provided between the outer nozzle member 2 and the nozzle body3 for elastically urging the nozzle body 3 toward a predetermined side(downward side in FIG. 13) in the displacement direction (upward anddownward in FIG. 13). The second suction passage 3 a extends in thedisplacement direction of the nozzle body 3. One end (lower end in FIG.13) of the second suction passage 3 a is open at a front end face 3 b(lower end face in FIG. 13) of the nozzle body 3 in the displacementdirection, whereas the other end (upper end in FIG. 13) thereof is openat a rear end face 3 c (upper end face in FIG. 13) of the nozzle body 3in the displacement direction to allow communication with the firstsuction passage 2 a.

[0004] The suction nozzle 1 is removably attached to a nozzle shaft 6 ofa mounting head section 5 of the electronic component mounting apparatusby a nozzle holder 7. The nozzle holder 7 includes an inner sleeve 7 bholding balls 7 a inside and an outer sleeve 7 c into which the innersleeve 7 b is pressed. The balls 7 a are fitted into engaging concave 2b formed on the outer nozzle member 2, and thus the suction nozzle 1 issecured to the nozzle shaft 6.

[0005] A suction passage 6 a of the nozzle shaft 6 is in communicationwith a vacuum suction pump 8. Thus, the electronic component B is heldby being sucked at the front end face 3 b of the nozzle body 3 with asuction force of the vacuum suction pump 8 acting through the suctionpassage 6 a of the nozzle shaft 6, the first suction passage 2 a of theouter nozzle member 2, and the second suction passage 3 a of the nozzlebody 3. The nozzle shaft 6 is mechanically connected to an elevationmechanism 9 and a rotation drive mechanism 10. The suction nozzle 1therefore moves up and down together with the nozzle shaft 6 by theelevation mechanism 9, and rotates around its axis together with thenozzle shaft 6 by the rotation drive mechanism 9.

[0006] When the electronic component B is to be picked up by suctionfrom a component feeder section (not shown) of the electronic componentmounting apparatus, the suction nozzle 1 is lowered to a predeterminedheight position (suction height position), where the front end face 3 bof the nozzle body 3 comes into contact with the electronic component B.The electronic component B is then sucked to the front end face 3 b ofthe nozzle body 3 with the suction force of the vacuum suction pump 8.The suction nozzle 1 holding the electronic component B by suction islifted to the original height position.

[0007] When the electronic component B is to be placed on a circuitboard (not shown), the suction nozzle 1 is lowered to a predeterminedheight position (placement height position), where the electroniccomponent B comes into contact with the circuit board. The suctionnozzle 1 is further lowered to apply a load to the electronic componentB that has been already in contact with the circuit board. By thisapplication of a load, the electronic component B is placed on thecircuit board.

[0008] The spring 4 is provided for absorbing the impact applied to thecomponent during suction-and placement of the component. Morespecifically, the spring 4 absorbs the impact applied to the component Bwhen the component B comes into contact with the nozzle body 3 duringthe component suction. The spring 4 also absorbs the impact applied tothe component B when the component B comes into contact with the circuitboard during the component mounting. In consideration of only thisimpact absorbing function, the urging force of the spring 4 ispreferably as small as possible.

[0009] During the suction of the electronic component B by the suctionnozzle 1, the suction force provided by the vacuum suction pump 8 alsoacts on the rear end face 3 c (upper end face in FIG. 13) of the nozzlebody 3, urging the nozzle body 3 in the direction in which the spring 4is compressed. If this suction force causes the nozzle body 3 to bedisplaced and changes the height position of the front end face 3 b ofthe nozzle body 3, a suction error and a placement error of theelectronic component B may occur. In order to avoid this displacement ofthe nozzle body 3 with respect to the outer nozzle member 2 due to thesuction force, the urging force of the spring 4 is conventionally set ata relatively large value (for example, 3.92 to 5.88 N (400 to 600 gf))so that the urging force can resist the suction force acting on thenozzle body 3.

[0010] However, the large urging force of the spring 4 inevitablyreduces the impact absorbing function. Namely, the large urging force ofthe spring 4 results in that a relatively high load is applied to theelectronic component B when the suction nozzle 1 comes into contact withthe electronic component B during the component suction. Likewise, arelatively high load is applied to the electronic component B when theelectronic component comes into contact with the circuit board duringthe component placement.

[0011] Some recent electronic components, on a back surface thereof,have solder balls which are to be crushed to an appropriate diameter bya load during placement. Such small-size electronic components must beplaced with a low load. If a high load is applied to such electroniccomponents during placement, the solder balls will be crushedexcessively. In view of this point, above-described conventional suctionnozzle 1 is not suitable for mounting the small-size electroniccomponents having the solder balls on the back surface thereof.

DISCLOSURE OF INVENTION

[0012] An object of the present invention is to provide a suction nozzlecapable of preventing displacement of a nozzle body due to suction andalso sufficiently absorbing the impact on a component during suction andplacement of the component.

[0013] A first aspect of the invention provides A suction nozzle forholding a component by suction, comprising: an outer nozzle memberdefining a first suction passage for communicating with a suction sourceat one end thereof and a nozzle body accommodation bore; a nozzle bodyfor holding the component at a distal end face thereof by suction,having a proximal side accommodated in the nozzle body accommodationbore so as to be slidable in a direction of an axis thereof and a distalside protruding from the outer nozzle member, the nozzle body defining asecond suction passage extending in the axis direction thereof forcommunicating with the first suction passage, and the second suctionpassage having an open at the distal end face of the nozzle body; and anurging member for urging the nozzle body in a direction away from theouter nozzle member, the urging member being accommodated in an urgingmember accommodation chamber defined by at least a wall surface of thenozzle body accommodation bore and a proximal end face of the nozzlebody.

[0014] The suction nozzle of the present invention includes the urgingmember accommodation chamber formed at the proximal side of the nozzlebody in which the urging member is accommodated. The urging memberaccommodation chamber shut off from the first and second passages. Withthis construction, it is possible to reduce the suction force from thesuction source acting on the nozzle body in the direction in which theurging member is compressed. Therefore, the urging force of the urgingmember can be set small without causing displacement of the nozzle bodyduring the suction. By setting a small urging force for the urgingmember, it is possible to sufficiently absorb the impact on thecomponent during the suction and placement of the component. Especially,when the urging member accommodation chamber communicates withatmosphere, reduction of the urging force of the urging member action onthe nozzle body is more effectively achieved.

[0015] Specifically, the nozzle body is provided with a firstcylindrical portion protruding from the proximal end face thereof. Thenozzle body is movable against an urging force of the urging member froma first position, where a distal end face of the first cylindricalportion is apart from a bottom wall surface of the nozzle bodyaccommodation bore, to a second position where the distal end face ofthe first cylindrical portion contacts against the bottom wall surfaceof the nozzle body accommodation bore.

[0016] After the nozzle body reaches the second position, the nozzlebody moves integrally with the outer nozzle member. During componentplacement, therefore, the suction nozzle in this state presses thecomponent against the circuit formation object, applying a load requiredfor the mounting. This load can be set irrespective of the urging forceof the urging member.

[0017] The urging member may be a spring. The urging force of thespring, for example, may be set not less than 0.196 N and not more than0.98 N.

[0018] A first annular groove for enlarging the diameter of the nozzlebody accommodation bore may be formed on a portion of the sideperipheral wall surface of the nozzle body accommodation bore adjacentto the bottom wall surface. The existence of the first annular groovecan reduce sliding resistance generated when the nozzle body moves inthe nozzle body accommodation bore. In addition, this prevents intrusionof an end of the first cylindrical portion of the nozzle body into theperipheral wall surface of the nozzle body accommodation bore.

[0019] A countersink may be formed on the bottom wall surface forsecuring the urging member. By being secured to the countersink, theurging member is stably held in the urging member accommodation chamberand thus prevented from intruding between the outer nozzle member andthe nozzle body.

[0020] The structure for communication of the first suction passage withthe second suction passage is not specifically restricted. For example,the nozzle body may define at least one lateral passage extending in adirection crossing the axis of the nozzle body and communicating withthe second suction passage at one end thereof, and the other end of thelateral passage may communicate with the other end of the first suctionpassage of the outer nozzle member.

[0021] The nozzle body may define a single lateral passage.Alternatively, the nozzle body may define two lateral passages, and thetwo lateral passages may be symmetric with respect to the axis of thenozzle body so that the suction force from the suction source uniformlyacts on the outer side peripheral wall surface of the nozzle body.

[0022] In order to attain further uniform suction force acting on theouter side peripheral wall surface of the nozzle body, a second annulargroove may be formed around the outer side peripheral wall surface ofthe nozzle body, and the lateral passage may be allowed to communicatewith the other end of the first suction passage through the secondannular groove.

[0023] Alternatively, the nozzle body may include a second cylindricalportion extending in the axis direction from the proximal end face. Thesecond cylindrical portion may extend through the urging memberaccommodation chamber into the first suction passage. The second suctionpassage may be allowed to communicate with the first suction passagethrough a third suction passage formed through the second cylindricalportion. With this construction, the spring accommodation chamber can beshut off from the first and second suction passages more reliably.

[0024] The outer nozzle member may define a first vacuum breakingpassage communicating with atmosphere at one end thereof. Further, thenozzle body may define a second vacuum breaking passage communicatingwith the second suction passage at one end thereof. The other ends ofthe first and second vacuum breaking passages are shut off from eachother when the suction nozzle holds the component by suction. On theother hand, the other ends of the first and second vacuum breakingpassages communicate with each other when the suction nozzle places thecomponent onto a circuit formation object.

[0025] The other ends of the first and second vacuum breaking passagesmay be shut off from each other when the nozzle body is in the firstposition, and may communicate with each other when the nozzle body is inthe second position, allowing the second suction passage to be open toatmosphere. With this construction, the sucking of the component to thenozzle body can be released smoothly and reliably when the nozzle bodycomes into contact with the outer nozzle member. For example, when thecomponent sucked to at nozzle body is pressed against the circuitformation objection and thus the nozzle body reaches the secondposition, the first and second vacuum breaking passages communicate witheach other, therefore resulting in the release of the suction.

[0026] A second aspect of the present invention provides a componentmounting apparatus for placing a component on a circuit formationobject, comprising: a component feeder section for feeding thecomponent; a circuit formation object transfer section for transferringthe circuit formation object to a component placement location; and amounting head section provided with the above-mentioned suction nozzle,the mounting head section being moved from the component feeder sectionto the component placement location, wherein when the mounting headsection is situated at a position corresponding to the component feedersection, the suction nozzle holds the component fed from the componentfeeder section by sucking the component at the distal end of the nozzlebody, and wherein when the mounting head section is situated at thecomponent placement location, the suction nozzle moves toward thecircuit formation object and places the component sucked at the distalend of the nozzle body onto the circuit formation object.

[0027] A third aspect of the present invention provides a method formounting a component on a circuit formation object using a suctionnozzle comprising an outer nozzle member, a nozzle body slidable in adirection of an axis thereof with respect to the outer nozzle member,and an urging member for urging the nozzle body in a direction away fromthe outer nozzle member comprising: holding the component by suction ata distal end of the nozzle body; moving the suction nozzle to a positionabove the circuit formation object; moving the suction nozzle in thedirection of the axis of the nozzle body toward the circuit formationobject to reach a first height position where the component sucked atthe distal end of the nozzle body comes into contact with the circuitformation object while the urging member absorbs an impact on thecomponent caused by the contact with the circuit formation object;moving the suction nozzle in the direction of the axis of the nozzlebody toward the circuit formation object, from the first height positionto a second position where a proximal side of the nozzle body is engagedwith the outer nozzle member, with moving the nozzle body with respectto the outer nozzle member against an urging force of the urging member;and further moving the suction nozzle in the direction of the axis ofthe nozzle body, from the second height position toward the circuitformation object, so that a load is applied to the component from thenozzle body, the component being placed onto the circuit formationobject by the load. The sucking of the component by the nozzle body maybe released when the suction nozzle reaches the second height position.

BRIEF DESCRIPTION OF DRAWINGS

[0028]FIG. 1 is a perspective view illustrating an electronic componentmounting apparatus provided with a suction nozzle of the presentinvention;

[0029]FIG. 2 is a vertical cross-sectional view illustrating a suctionnozzle of the first embodiment;

[0030]FIG. 3 is a vertical cross-sectional view illustrating the suctionnozzle of the first embodiment:

[0031]FIG. 4A is a cross-sectional view taken along line IV-IV in FIG.2;

[0032]FIG. 4B is a cross-sectional view taken along line IV′-IV′ in FIG.2;

[0033]FIG. 4C is a cross-sectional view taken along line IV″-IV″ in FIG.2;

[0034]FIG. 5A is a partial enlarged view of a portion V in FIG. 2;

[0035]FIG. 5B is a partial enlarged view of a portion V′ in FIG. 3;

[0036]FIG. 6 is a vertical cross-sectional view illustrating a suctionnozzle of the second embodiment of the present invention;

[0037]FIG. 7 is a cross-sectional view taken along line VII-VII in FIG.6;

[0038]FIG. 8 is a vertical cross-sectional view illustrating a suctionnozzle of the third embodiment of the present invention;

[0039]FIG. 9 is a vertical cross-sectional view illustrating the suctionnozzle of the third embodiment of the present invention;

[0040]FIG. 10A is a cross-sectional view taken along line X-X in FIG. 8;

[0041]FIG. 10B is a cross-sectional view taken along line X′-X′ in FIG.9;

[0042]FIG. 11 is a vertical cross-sectional view illustrating a suctionnozzle of the fourth embodiment of the present invention;

[0043]FIG. 12 is a cross-sectional view taken along line XII-XII in FIG.11; and

[0044]FIG. 13 is a vertical cross-sectional view illustrating aconventional suction nozzle.

BEST MODE FOR CARRYING OUT THE INVENTION

[0045] The present invention will now be described in detail inaccordance with embodiments illustrated in the drawings.

First Embodiment

[0046]FIG. 1 illustrates an electronic component mounting apparatus 100provided with a suction nozzle 21 of the present invention. FIGS. 2 to 5illustrate the suction nozzle 21 of the first embodiment.

[0047] Referring to FIG. 1, the electronic component mounting apparatus100 includes: a board transfer section 101 for transferring a circuitboard A; component feeder sections 102 including a plurality ofcomponent feeder units; a mounting head section 103 to which the suctionnozzle 21 can be attached; a board recognition camera 104 forrecognizing the circuit board A; an X-Y robot 105 capable of moving themounting head section 103 and the board recognition camera 104 indirections shown by arrows X and Y in FIG. 1; component imaging units106 for imaging the posture of an electronic component B sucked and heldby the suction nozzle 21; component discard sections 107 for discardingthe electronic component B if the posture thereof is found abnormal; anda control unit 108 for controlling these operations.

[0048] Referring to FIG. 2, the suction nozzle 21 is removably attachedto a nozzle shaft 22 of the mounting head section 103 by a nozzle holder23. Specifically, the nozzle holder 23 includes an inner sleeve 23 bholding balls 23 a inside and an outer sleeve 23 c in which the innersleeve 23 b is pressed. The balls 23 a are fitted into engage concave 38formed on an outer nozzle member 30 to be described later, and thus thesuction nozzle 21 is secured to the nozzle shaft 22.

[0049] A suction passage 22 a of the nozzle shaft 22 is in communicationwith a vacuum suction pump 24. The nozzle shaft 22 is mechanicallyconnected to an elevation mechanism 26 and a rotation drive mechanism27. The suction nozzle 21 therefore moves up and down together with thenozzle shaft 22 by the elevation mechanism 26, and rotates around anaxis thereof together with the nozzle shaft 22 by the rotation drivemechanism 27.

[0050] The suction nozzle 21 includes the outer nozzle member 30, anozzle body 40, and a spring 50.

[0051] The outer nozzle member 30 is formed with a first suction passage31 and a nozzle body accommodation bore 32. The first suction passage 31includes: a comparative large-diameter first portion 31 a communicatingwith the suction passage 22 a of the nozzle shaft 22; a second portion31 b communicating with the first portion 31 a at one end thereof andextending in the direction of an axis L of the nozzle body 40; and athird portion 31 c extending from the other end of the second portion 31b in a direction perpendicular to the second portion 31 b. The thirdportion 31 c is open at a side peripheral wall surface 32 a of thenozzle body accommodation bore 32.

[0052] A proximal side of the nozzle body 40 is accommodated in thenozzle body accommodation bore 32 of the outer nozzle member 30 so as tobe slidable in the direction of the axis L thereof. An outer sideperipheral wall surface 40 a of the nozzle body 40 closely or airtightlytouches the side peripheral wall surface 32 a of the nozzle bodyaccommodation bore 32. A distal side of the nozzle body 40 protrudesfrom the outer nozzle member 30 downward as shown in FIG. 2.

[0053] The nozzle body 40 is formed with a second suction passage 41that extends in the direction of the axis L and is open at a distal endface 40 b thereof. The nozzle body 40 is also formed with a lateralpassage 42 extending in a direction perpendicular to the axis L. Thelateral passage 42 communicates with the second suction passage 41 atone end thereof and is open at the outer side peripheral wall surface 40a of the nozzle body 40 at the other end thereof.

[0054] As shown in FIGS. 2 and 4A, an annular groove 43 is formed at aposition of the outer side peripheral wall surface 40 a of the nozzlebody 40 corresponding to the opening of the lateral passage 42. Thesecond suction passage 41 communicates with the third portion 31 c ofthe first suction passage 31 through the annular groove 43 and thelateral passage 42. As shown in FIGS. 2 and 4B, a first cylindricalportion 44 protrudes from a proximal end face 40 c of the nozzle body 40in the direction of the axis L. As shown in FIGS. 5A and 5B, the distalend of the cylindrical portion 44 is beveled as denoted by referencenumeral 44 a to facilitate insertion of the nozzle body 40 into thenozzle body accommodation bore 32 during manufacture.

[0055] A space shut off from the first and second suction passages 31,41, that is, a spring accommodation chamber 60 is defined by theproximal end face 40 c of the nozzle body 40, a bottom wall surface 32 bof the nozzle body accommodation bore 32, the side peripheral wallsurface 32 a of the nozzle body accommodation bore 32, and the firstcylindrical portion 44. As shown in FIGS. 2 and 4B, the springaccommodation chamber 60 communicates with atmosphere through anelliptical bore 44 b formed through the first cylindrical portion 44 anda circular sectional passage 33 formed at a position of the outer nozzlemember 30 corresponding to the elliptical bore 44 b. Therefore, thepressure in the spring accommodation chamber 60 is kept at atmosphericpressure irrespective of the position of the nozzle body 40 with respectto the outer nozzle member 30 and the existence or absence of a suctionforce applied by the vacuum suction pump 24. In other words, the suctionforce of the vacuum suction pump 24 does not act on the proximal endface 40 c of the nozzle body 40.

[0056] A helical spring 50 is accommodated in the compression state inthe spring accommodation chamber 60. The spring 50 elastically urges thenozzle body 40 in the direction away from the outer nozzle member 30.Since the suction force of the vacuum suction pump 24 does not act onthe proximal end face 40 c of the nozzle body 40 as described above, theurging force of the spring 50 is not required to be large to resist thesuction force. Therefore, the urging force of the spring 50 can be setat a relatively small value. Specifically, the urging force of thespring 50 may be set not less than 0.196 N and not more than 0.98 N.

[0057] Accommodation of the spring 50 in the spring accommodationchamber 60 will be described in detail. The spring 50 is placed insidethe cylindrical portion 44. Countersinks 71A, 71B are each formed on theproximal end face 40 c of the nozzle body 40 and the bottom wall surface32 b of the nozzle body accommodation bore 32 both defining the springaccommodation chamber 60. Ends of the spring 50 are each inserted in thecountersinks 71A, 71B, so that the spring 50 is stably held in thespring accommodation chamber 60. Thus, the spring 50 is prevented fromintruding into the space between the outer nozzle member 30 and thenozzle body 40.

[0058] As shown in FIGS. 2, 4C, 5A, and 5B, an annular groove 34 isformed at a position of the side peripheral wall surface 32 a of thenozzle body accommodation bore 32 adjacent to the bottom wall surface 32b. A diameter of the nozzle body accommodation bore 32 is larger in thisportion with the annular groove 34 than the other portion. Therefore, inthis portion, the first cylindrical portion 44 of the nozzle body 40 isnot contact with the side peripheral wall surface 32 a of the nozzlebody accommodation bore 32 as shown in FIGS. 5A and 5B. Thisadvantageously reduces the sliding resistance on the nozzle body 40 whenit slides inside the nozzle body accommodation bore 32. In addition, theexistence of the annular groove 34 prevents the distal end of the firstcylindrical portion 44 to be engaged in the side peripheral wall 32 a ofthe nozzle body accommodation bore 32.

[0059] An engage groove 45 extending in the direction of the axis L isformed on the outer side peripheral wall surface 40 a of the nozzle body40. A stopper 72 secured to the outer nozzle member 30 is looselyinserted in the engage groove 45 so that a distal end of the stopper 72is movable in the engage groove 45. By engagement of an end portion ofthe engage groove 45 with the stopper 72 as shown in FIG. 2, the nozzlebody 40 is prevented from coming off from the nozzle body accommodationbore 32 due to the urging force of the spring 50.

[0060] The suction force of the vacuum suction pump 24 acts on theelectronic component B at the distal end face 40 b of the nozzle body 40through the suction passage 22 a of the nozzle shaft 22, the firstsuction passage 31 of the outer nozzle member 30, the annular groove 43of the nozzle body 40, the lateral passage 42 of the nozzle body 40, andthe second suction passage 41 of the nozzle body 40. With the existenceof the annular groove 43 of the nozzle body 40, the suction force of thevacuum suction pump 24 fails to directly act on the outer sideperipheral wall surface 40 a of the nozzle body 40 at a junction betweenthe first suction passage 31 of the outer nozzle member 30 and thelateral passage 42 of the nozzle body 40. This prevents the nozzle body40 from being sucked to the outer nozzle member 30 at the junction dueto the suction force of the vacuum suction pump 24, and thus ensuresreduction in sliding resistance generated when the nozzle body 40 isdisplaced with respect to the outer nozzle member 30.

[0061] When no force upward along the axis L acts to the distal end face40 b, the nozzle body 40 is in first position shown in FIG. 2 where thenozzle body 40 is stopped by the stopper 72. In this first position, asshown in FIG. 5A, an end face 44 c of the first cylindrical portion 44of the nozzle body 40 is apart from the bottom wall surface 32 b of thenozzle body accommodation bore 32. Once a force upward along the axis Lacts to the distal end face 40 b, the nozzle body 40 moves upwardlytoward second position shown in FIG. 3 against the urging force of thespring 50. In this second position, as shown in FIG. 5B, the end face 44c of the first cylindrical portion 44 of the nozzle body 40 is incontact with the bottom wall surface 32 b of the nozzle bodyaccommodation bore 32.

[0062] Then, the operation of the electronic component mountingapparatus 100 having the suction nozzle 21 will be described.

[0063] First, the board transfer section 101 transfers the circuit boardA to a component placement location. During this transfer, the boardrecognition camera 104 is moved to be located above the circuit board Aby the X-Y robot 105 to recognize a position on the circuit board A atwhich the electronic component B is to be placed.

[0064] The mounting head section 103 is then moved to the componentfeeder section 102 by the X-Y robot 105, where the suction nozzle 21sucks and holds the electronic component B fed from the component feedersection 102 in the following manner.

[0065] First, the suction nozzle 21 is lowered to a predetermined heightposition (suction height position) by the elevation mechanism 26, toallow the distal end face 40 b of the nozzle body 40 to come intocontact with the electronic component B fed from the component feedersection 102. In this occasion, the impact applied to the electroniccomponent B can be sufficiently absorbed since the urging force of thespring 50 is relatively small as described above.

[0066] Subsequently, the electronic component B is sucked to the distalend face 40 b of the nozzle body 40 with a suction force of the vacuumsuction pump 24 acting through the first suction passage 31 of the outernozzle member 30, the lateral passage 42 of the nozzle body 40, and thesecond suction passage 41 of the nozzle body 40. In this occasion, thenozzle body 40 is prevented from being displaced with respect to theouter nozzle member 30 due to the suction force of the vacuum suctionpump 24. This is because that the spring accommodation chamber 60provided at the proximal side of the nozzle body 40 serves to reduce thesuction force of the vacuum suction pump 24 acting on the nozzle body 40in the direction of the axis L (direction in which the spring 50 iscompressed). It is therefore possible to keep constant the heightposition of the distal end face 40 b of the nozzle body 40 holding theelectronic component B by suction. Thereafter, the suction nozzle 21holding the electronic component B is moved upwardly to the originalheight position by the elevation mechanism 26.

[0067] The mounting head section 103 is then moved by the X-Y robot 105so that the electronic component B held by the suction nozzle 21 passesover the component imaging device 106. During this passing, thecomponent imaging device 106 takes an image of the posture of theelectronic component B held by the suction nozzle 21. Based on theresults of this imaging, the control unit 108 determines whether or notthe posture of the electronic component B is appropriate. If the postureof the electronic component B is determined appropriate, the position ofthe electronic component B is then corrected based on the imageinformation obtained. More specifically, the suction nozzle 21 isrotated around the axis L by the rotation drive mechanism 27 to correctthe rotational position of the electronic component B.

[0068] Thereafter, the mounting head section 103 is moved to thecomponent mounting location by the X-Y robot 105, where the electroniccomponent B held by the suction nozzle 21 is placed onto the circuitboard A in the following manner. First, the suction nozzle 21 is loweredto a predetermined height position (placement height position) by theelevation mechanism 26, to allow the electronic component B sucked atthe distal end face 40 b to come into contact with the circuit board A.In this occasion, the impact applied to the electronic component B canbe sufficiently absorbed since the urging force of the spring 50 isrelatively small as described above.

[0069] The suction nozzle 21 is further lowered from the placementheight position. As a result, the nozzle body 40 moves toward the outernozzle member 30 against the urging force of the spring 50 to reach thesecond position (see FIG. 2). In this occasion, only a small load isapplied to the electronic component B since the urging force of thespring 50 is relatively small.

[0070] In the second position, the end face 44 c of the firstcylindrical portion 44 of the nozzle body 40 is in contact with thebottom wall surface 32 b of the nozzle body accommodation bore 32 of theouter nozzle member 30 as described above. Therefore, as the suctionnozzle 21 is further lowered, the nozzle body 40 is lowered togetherwith the outer nozzle member 30 without being displaced with respect tothe outer nozzle member 30. As a result, a load is applied from thenozzle body 40 to the electronic component B that has been already incontact with the circuit board A. With this load, the electroniccomponent B is place onto the circuit board A. After completion of theplacement, the suction of the vacuum suction pump 24 is halted.Thereafter, the suction nozzle 21 is moved upwardly to the originalheight position.

[0071] If it is determined that the posture of the electronic componentB is inappropriate according to the imaging results by the componentimaging device 106, the mounting head section 103 is moved to thecomponent discard section 107 by the X-Y robot 105. In the componentdiscard section 107, the suction of the vacuum suction pump 24 isreleased to discard the electronic component B sucked to the suctionnozzle 21.

Second Embodiment

[0072]FIGS. 6 and 7 illustrate a suction nozzle 21 of the secondembodiment of the present invention. In this embodiment, the nozzle body40 includes two lateral passages 42, 42 formed symmetrically withrespect to the axis L of the nozzle body 40. Namely, these lateralpassages 42, 42 are formed at positions apart from each other by 180degrees with respect to the axis L. In addition, the first suctionpassage 31 of the outer nozzle member 30 includes two second portions 31b, 31 b and two third portions 31 c, 31 c to communicate with the twolateral passages 42, 42. These second portions 31 b, 31 b and thirdportions 31 c, 31 c are also formed at positions apart from each otherby 180 degrees with respect to the axis L.

[0073] In the second embodiment, the suction force of the vacuum suctionpump 24 acts on the second suction passage 41 of the nozzle body 40through the two lateral passages 42, 42. This makes more uniform thesuction force acting on the outer side peripheral wall surface 40 a ofthe nozzle body 40, and thus more reliably prevents the nozzle body 40from being sucked to the outer nozzle member 30 due to the suction forceof the vacuum suction pump 24. As a result, sliding resistance can bereduced more reliably during the displacement of the nozzle body 40 withrespect to the outer nozzle member 30.

[0074] The other construction and function of the second embodiment arethe same as those of the first embodiment described above. Therefore,the same components are denoted by the same reference numerals, and thedescription thereof is omitted.

Third Embodiment

[0075] FIGS. 8 to 10 illustrate the third embodiment of the presentinvention. In the third embodiment, a first vacuum breaking passage 36is formed in the outer nozzle member 30 and a second vacuum breakingpassage 46 is formed in the nozzle body 40. The first vacuum breakingpassage 36 communicates with atmosphere at one end thereof and is openat the side peripheral wall surface 32 a of the nozzle bodyaccommodation bore 32 at the other end thereof. The second vacuumbreaking passage 46 communicates with the second suction passage 41 atone end thereof and is open at the outer side peripheral wall surface 40a of the nozzle body 40 at the other end thereof.

[0076] As shown in FIGS. 8 and 10A, when the nozzle body 40 is in thefirst position, the other ends of the first and second vacuum breakingpassage 36, 46 are shut off from each other. In the first position,however, the first suction passage 31 and the second suction passage 41communicate with each other. Therefore, when the nozzle body 40 is inthe first position, the electronic component B is sucked at the distalend face 40 b of the nozzle body 40 with the suction force of the vacuumsuction pump 24 acting through the first and second suction passages 31,41.

[0077] On the contrary, as shown in FIGS. 9 and 10B, when the nozzlebody 40 is in the second position, the other ends of the first andsecond vacuum breaking passages 36, 46 communicate with each other. Inthe second position, however, the position of the annular groove 43 isdisplaced from the position of the third portion 31 c of the firstsuction passage 31, blocking communication between the first and secondsuction passages 31, 41. Therefore, without blowing action for releasingthe electronic component B, only displacement of the nozzle body 40 tothe second position and the halt of the suction of the vacuum suctionpump 24 attain smooth and reliable release of sucking of the electroniccomponent B at the distal end face 40 b of the nozzle body 40.

[0078] For example, when the suction nozzle 21 sucking and holding theelectronic component B at the nozzle body 40 is further lowered from theplacement height position so that the nozzle body 40 reaches the secondposition and the suction of the vacuum suction pump 24 is halted, theelectronic component B is released from being sucked. The suction forceno more acts on the electronic component B during the further loweringof the suction nozzle 21 from the placement height position to apply aload to the electronic component B for placing on the circuit board A.

[0079] The other construction and function of the third embodiment arethe same as those of the first embodiment described above. Therefore,the same components are denoted by the same reference numerals, and thedescription thereof is omitted.

Fourth Embodiment

[0080]FIGS. 11 and 12 illustrate the fourth embodiment of the presentinvention. In the fourth embodiment, a second cylindrical portion 47protrudes in the direction of the axis L coaxially with the firstcylindrical portion 44. A third suction passage 47 a formed through thesecond cylindrical portion 47 communicates with the second suctionpassage 41 at one end thereof and is open at the distal end face of thesecond cylindrical portion 47 at the other end thereof.

[0081] The outer nozzle member 30 has a through bore 37 extending fromthe bottom wall surface 32 b of the nozzle body accommodation bore 32 tothe first suction passage 31. The second cylindrical portion 47 extendsthrough the spring accommodation chamber 60 and then the through hole 37to the first suction passage 31.

[0082] The spring accommodation chamber 60 is defined by the sideperipheral wall surface 32 a and the bottom wall surface 32 b of thenozzle body accommodation bore 32, the first cylindrical portion 44, andan outer side peripheral wall surface of the second cylindrical portion47. As in the first embodiment, the spring accommodation chamber 60communicates with atmosphere through the elliptical bore 44 a formedthrough the first cylindrical portion 44 and the passage 33 formedthrough the outer nozzle member 30.

[0083] In the fourth embodiment, the first and second suction passages31, 41 communicate with each other through the third suction passage 47a of the second cylindrical portion 47. With this construction, thespring accommodation chamber 60 is shut off more reliably from the firstand second suction passages 31, 41.

[0084] The other construction and function of the fourth embodiment arethe same as those of the first embodiment described above. Therefore,the same components are denoted by the same reference numerals, and thedescription thereof is omitted. The suction nozzle of the fourthembodiment may be provided with the first and second vacuum breakingpassages of the third embodiment.

[0085] In the first through fourth embodiments, the spring accommodationchamber 60 communicates with atmosphere as described above. However, thespring accommodation chamber 60 may be airtightly enclosed chamber shutoff from not only the first and second suction passages 31, 41 but alsoatmosphere. This construction also achieves reduction of the suctionforce by the vacuum suction pump 24 acting to the nozzle body 40.

[0086] Although the present invention has been fully described by way ofthe examples with reference to the accompanying drawings, it is to benoted here that various changes and modifications will be apparent tothose who skilled in the art. Therefore, unless such changes andmodifications otherwise depart from the spirit and scope of the presentinvention, they should be construed as being therein.

1. A suction nozzle (21) for holding a component (B) by suction,comprising: an outer nozzle member (30) defining a first suction passage(31) for communicating with a suction source (24) at one end thereof anda nozzle body accommodation bore (32); a nozzle body (40) for holdingthe component (B) at a distal end face (40 b) thereof by suction, havinga proximal side accommodated in the nozzle body accommodation bore so asto be slidable in a direction of an axis (L) thereof and a distal sideprotruding from the outer nozzle member, the nozzle body defining asecond suction passage (41) extending in the axis direction thereof forcommunicating with the first suction passage, and the second suctionpassage having an open at the distal end face of the nozzle body; and anurging member (50) for urging the nozzle body in a direction away fromthe outer nozzle member, the urging member being accommodated in anurging member accommodation chamber (60) defined by at least a wallsurface of the nozzle body accommodation bore and a proximal end face(40 c) of the nozzle body.
 2. A suction nozzle according to claim 1,wherein the urging member accommodation chamber communicates withatmosphere.
 3. A suction nozzle according to claim 1, wherein the nozzlebody is provided with a first cylindrical portion (44) protruding fromthe proximal end face thereof, and wherein the nozzle body is movableagainst an urging force of the urging member from a first position,where a distal end face of the first cylindrical portion is apart from abottom wall surface (32 b) of the nozzle body accommodation bore, to asecond position where the distal end face of the first cylindricalportion contacts against the bottom wall surface of the nozzle bodyaccommodation bore.
 4. A suction nozzle according to claim 1, wherein afirst annular groove (34) for enlarging a diameter of the nozzle bodyaccommodation bore is formed on a portion of a side peripheral wallsurface (32 a) of the nozzle body accommodation bore adjacent to thebottom wall surface.
 5. A suction nozzle according to claim 1, whereinthe nozzle body defines at least one lateral passage (42) extending in adirection crossing the axis thereof, and wherein the lateral passagecommunicates with the second suction passage at one end thereof andcommunicates with the other end of the first suction passage of theouter nozzle member at the other end thereof.
 6. A suction nozzleaccording to claim 5, wherein the nozzle body defines a single lateralpassage.
 7. A suction nozzle according to claim 5, wherein the nozzlebody defines two lateral passages, and wherein the lateral passages arearranged symmetrically with respect to the axis of the nozzle body.
 8. Asuction nozzle according to claim 5, wherein a second annular groove(43) is formed on an outer side peripheral wall surface (40 a) of thenozzle body, and wherein the lateral passage communicates with the otherend of the first suction passage through the second annular groove.
 9. Asuction nozzle according to claim 1, wherein the nozzle body is providedwith a second cylindrical portion (47) protruding from the proximal endface thereof in the axis direction thereof, wherein the secondcylindrical portion extends through the urging member accommodationchamber into the first suction passage of the outer nozzle member, andwherein the second suction passage communicates with the first suctionpassage through a third suction passage (47 a) formed through the secondcylindrical portion.
 10. A suction nozzle according to claim 1, whereinthe outer nozzle member defines a first vacuum breaking passage (36)communicating with atmosphere at one end thereof, wherein the nozzlebody defines a second vacuum breaking passage (46) communicating withthe second suction passage at one end thereof, wherein the other ends ofthe first and second vacuum breaking passages are shut off from eachother when the suction nozzle holds the component by suction, andwherein the other ends of the first and second vacuum breaking passagescommunicate with each other when the suction nozzle places the componentonto a circuit formation object (A).
 11. A suction nozzle according toclaim 3, wherein the outer nozzle member defines a first vacuum breakingpassage (36) communicating with atmosphere at one end thereof, whereinthe nozzle body defines a second vacuum breaking passage (46)communicating with the second suction passage at one end thereof,wherein the other ends of the first and second vacuum breaking passagesare shut off from each other when the nozzle body is in the firstposition, and wherein the other ends of the first and second vacuumbreaking passages communicate with each other when the nozzle body is inthe second position, allowing the second suction passage to be open toatmosphere.
 12. A component mounting apparatus (100) for placing acomponent (B) on a circuit formation object (A), comprising: a componentfeeder section (102) for feeding the component (B); a circuit formationobject transfer section (101) for transferring the circuit formationobject to a component placement location; and a mounting head section(103) provided with the suction nozzle (21) according to any one ofclaims 1 to 11, the mounting head section being moved from the componentfeeder section to the component placement location, wherein when themounting head section is situated at a position corresponding to thecomponent feeder section, the suction nozzle holds the component fedfrom the component feeder section by sucking the component at the distalend of the nozzle body (40), and wherein when the mounting head sectionis situated at the component placement location, the suction nozzlemoves toward the circuit formation object and places the componentsucked at the distal end of the nozzle body (40) onto the circuitformation object (A).
 13. A method for mounting a component (B) on acircuit formation object (A) using a suction nozzle (21) comprising anouter nozzle member (30), a nozzle body (40) slidable in a direction ofan axis (L) thereof with respect to the outer nozzle member, and anurging member (50) for urging the nozzle body in a direction away fromthe outer nozzle member comprising: holding the component by suction ata distal end of the nozzle body; moving the suction nozzle to a positionabove the circuit formation object; moving the suction nozzle in thedirection of the axis of the nozzle body toward the circuit formationobject to reach a first height position where the component sucked atthe distal end of the nozzle body comes into contact with the circuitformation object while the urging member absorbs an impact on thecomponent caused by the contact with the circuit formation object;moving the suction nozzle in the direction of the axis of the nozzlebody toward the circuit formation object, from the first height positionto a second position where a proximal side of the nozzle body is engagedwith the outer nozzle member, with moving the nozzle body with respectto the outer nozzle member against a elastic urging force of the urgingmember; and further moving the suction nozzle in the direction of theaxis of the nozzle body, from the second height position toward thecircuit formation object, so that a load is applied to the componentfrom the nozzle body, the component being placed onto the circuitformation object by the load.
 14. A method according to claim 13,further comprising releasing the sucking of the component by the nozzlebody when the suction nozzle reaches the second height position.